Fluid engine



June 3, 19 41 c. w. H. D. BENNET- FLUID ENGINE 3 Sheets-Sheet 1 Filed June 20, 1939 1 72 ueni'o Uaal WJfiHEenneZ',

June 3, 1941. c, w. H. D. BENNET FLUID ENGINE Filed June 20, 1939 3 Sheets-Sheet 3 Inveni'or:

Patented June 3, 1941 FLUID ENGINE Carl Wilhelm Henrik Diicker Bennet, Stockholm,

Sweden, assignor to Louise Gunnila Violet Bennet, Runcborg, Stocksund, Sweden Application June 20, 1939, Serial No. 280,193 In Germany July 2, 1938 20 Claims.

The present invention relates to engines, such as pumps, compressors or motors, for liquid or gaseous working fluids of the type including a casing and a band therein which forms a portion of the wall of a working chamber in said casing and which is arranged to perform a uni-directional wave-like movement In an engine of this type previously known, the Working chamber is formed by a one-piece flexible tube of rubber or the like elastic non-metallic material, one side of the said tube forming the band to which wave-like movements are imparted. Such construction is, however, objectionable, since it renders impossible a perfect tightening of the working chamber and since the walls of the working chamber are subject to the detrimentalefiect of wear due to continuous tensile and bending stresses exerted on the material of which the walls consist.

It is one of the objects of the present invention to provide an improved construction of the working chamber for the purpose of avoiding the above named inconveniences.

In the above named known engine, the wall of the working chamber receives the Wave-like movement by means of a great number of cocentrics connected to the wall and arranged to rotate in staggered'angular relationship. It is a further object of this invention to simplify the known construction with a view to reduce the number of the diiferent parts of the engine and thereby to diminish the cost and mechanical losses of the engine;

I attain these and other objects by mechanism illustrated in the accompanying drawings, in which:

Fig. 1 illustrates a pump constructed in accordance with the invention and comprising a helix and two bands adapted to receive a unidirectional wave-like movement by means of the helix;

Fig. 2 is a side elevation of the pump shown in Fig; 1, the cover of the casing being omitted;

Fig. 3 is a section on the line 3-3 of Fig, 1:

Fig. 4'shows diagrammatically an apparatus according to the invention, in which wave-like movement is imparted to two bands by means of two helices;

Fig. 5 is a section on the line 55of Fig. 4;

Figure 6 shows a device for varying the eiiective length of the bands;

Figure 7 is a modification of the embodiment shown in Figure 6, said modification being provided with means for automatic variation of the distance.

Fig. 8 shows part of a helix with appeartaining bands formed by a wireand provided with inserted sealing elements;

Fig. 9 is a section on the line 9--9 of Fig. 8';

Fig. 10 is a section on an enlarged scale on the line Ill-40 of Fig. 9;

Fig. 11 is a section of a helix with appertaining wire and rubber cover;

tially square cross-section and provided with an inlet 22 and two outlets 23 and 24. It is assumed that the apparatus is intended to be operated as a liquid pump. 25 denotes a helically shaped rod which hereinafter is termed the helix. One end of the helix passes through the casing and through a bearing and tightening member 25 to the outside of the casing where rotation is imparted to the helix. In the present instance, there are provided two bands 2'! and 28 Which are located on both sides of the helix and which extend throughout the whole width of the casing so that they tightly fit the. walls 29 and 30 of the casing. Near the outlet, the helix passes through an end piece 3| pivoted in pins 32 and 33'and provided with an oblong opening 34, the width of which is substantially equal to the diameter of the rod forming the'helix 25. Therefrom it follows that upon a rotation of the helix the end piece 3| will be oscillated about the axis 32, 33. The end piece consists of two interconnected parts 35 and 35 between which the bands-21 and 2B are inserted in the manner indicated in Fig. 1. The ends of the bands will thus also be oscillated in a manner corresponding to the oscillatory movement of the bands, whereby rupture of the bands attheir places of connection is prevented.

;In a similar way, the lower ends of the bands are secured in an end piece 3'! pivotally mounted on pins 38 and 39. The end piece 3! carries a ball 40 against which rests the lower end of the helix 25.

In order that the bands may freely follow the wave-like movements of the helix they must be very flexible in the longitudinal direction, but as rigid as possible in the transverse direction. To this end, a plurality of thin bands may be provided on each side of the helix instead of a single band. Inthis case, the ends-of the bands should be movably connected with one of the end pieces so as to render possible mutual displacements of the bands in the longitudinal direction due to the wave-like movements of the band.

The helix 25 illustrated inFigs. 1 to 3 is in the form of a right-handed helix. Upon rotation of the helix in the direction indicated by the arrow M the working chambers 42 and 43 enclosed between the walls of the casing and the bands 21 and 28, respectively, will be displaced from the inlet 22 to the outlets 23 and 24, respectively, so that the liquid contained in the said working spaces will be pumped in the direction of the arrows 44, 45, 46. The working spaces 41 and 48 are still in communication with the inlet 22,

Whereas the working spaces 49 and 50 already: have been brought into communication with the outlets 49 and 50, respectively.

As will be seen from Figs. 1 to 3, the bands 21 and 28 and the remaining portions of the walls of the working chambers 42 and 43 consist of separate parts being independent of each other. During the operation of the engine, the places at which power is transmitted from the helix to the bands are moving in the longitudinal direction of the bands.

The bands work as endless pistons resulting in a, continuous uni-directional movement, and the apparatus will be operated as a displacement pump impelling a constant quantity of fluid per revolution of the helix. The apparatus may also be used 'for the propulsion of vehicles or vessels, in which case the bands and the helix may be provided in an open channel located in the longitudinal direction of the vessel, or for the propulsion of aircraft, such as aeroplanes in which case one or more devices according to the invention may be mounted in the wings of the aeroplane,

The apparatus may also be used for the production of power, in which case fluid under pressure is admitted to the apparatus and exerts pressure on the bands 21 and 28, whereby the helix is rotated and power can be taken on therefrom. Liquid, such as water, is preferably used as a motive fluid. V

The embodiment illustrated in Figs. 4 and 5 includes two helices 66 and 66a adapted to actuate two bands 61 and 68 located on both sides of the helices. For the sake of clearness, the bands are not shown in Fig. 4. One of the helices is devised as a left-handed helix and the other one as a right-handed helix. The helices are mechanically interconnected by means of gearings 69 and I0 and are so disposed that the crests and the troughs will always be located opposite each other. The helices are rotated in opposite directions. As will be apparent from Fig. 5, the cross-sections of the helices will, upon rotation of the helices, always be located symmetrically with respect to a plane of symmetry II disposed between the helices in a manner such that both cross-sections will simultaneously move toward or away from the said plane of symmetry. As compared with an arrangement in which two right-handed or two left-handed helices are employed, the construction shown offers the advantage that the pressures acting in the transverse direction of the bands will counterbalance each other and that the bands will be acted on symmetrically with respect to the plane of symmetry II 50 that they will not be subject to unbalanced bending movements.

In the embodiment shown in Figure 6, the bands 55 and 56 are secured to bearing sleeves 51 and 58. The bearing sleeve 51 is adjustably mounted in an end wall of the casing 2| and can be secured in diiferent positions by means of bolts 6| fixed in the casing and appertaining nuts 62 abutting againstan outer flange 63 of the sleeve 51. This construction permits of variation of the distance between the places of attachment of the bands and thus also the variation of the efiective length of the bands from a minimum distance to a maximum distance. In the former at the lower end thereof.

case, the waves of the bands correspond exactly to the waves of the helix, whereas in the latter case the bands are fully stretched out. By this adjustment of the efiective length of the bands, the capacity of the apparatus can be varied from a maximum value corresponding to the minimum distance between the places of attachment of the bands and naught corresponding to the maximum distance between the said places. Figure 6 illustrates the bands in their fully stretched-out positions. As shown in the modification illustrated in Figure '7, the bands may be adjusted automatically.

Fig. 6 illustrates an embodiment of the invention constructed as a mixing pump for two liquids the temperature of mixture of which is to be maintained at a certain value. I00 indicates the casing which is provided with two inlets IOI and I02 for the two liquids and a common outlet I03. I04 denotes the helix which is actuated The helix is adapted to actuate two bands I05 and I06 secured at their lower ends in a portion ID! of the casing. The upper ends of the bands are connected with pins I08 and I09, respectively, adapted to slide in stationary slots I I0 and III, respectively, extending in the longitudinal direction of the casing. The pins are guided in slots H2 and H3, respectively, provided in a plate H4. The directions of the slots H2 and H3 are such that upon displace- I-Tments of the plate II 4 toward the left the pin be moved in opposite directions.

The bands I05 and I05 abut partially only against the helix I04 so that the working chambers are smaller than the volumes provided between the helix and the walls of the casing. The

Zyolume of the Working chamber I I5 may be varied by increasing or decreasing the distance between the places of connection of the band I05. In the present embodiment such variation is effected by moving the pin I08 up or down in the slot If, for instance, the pin I08 is moved upwardly, the distance between the places of connection of the band is increased, that is, the band will be somewhat stretched, whereby the volume of the working chamber II5 will be reduced correspondingly. In a similar manner, the working chamber II 6 may be increased or reduced by moving the pin I09 in the slot III.

Adjacent to the outlet of the pump, there is provided arthermostat including a bellows II'I adapted to be expanded or contracted under the influence of variations in temperature and thereby to act'upon a lever H9 pivoted at II8 the lower arm I20 of which engages a recess I2I in the plate II4 so thatas the lever is turned about its pivot the plate will be shifted to the right or to the left. A spring I22 is arranged to counter act the influence of the bellows Ill.

The apparatus described operates in the following manner.

- Hot liquid is drawn in through the inlet NH and is pumped into the mixing chamber I23 through the working chambers located on the left side of the helix. Cold liquid is drawn in through the inlet I02 and is pumped into the mixing chamber I23 on the right-hand side of the helix. If the temperature of mixture prevailing in the chamber I23 has the desired value, the moments exerted upon the lever II9 by the bellows III and the spring I22 will balance each other, and

the lever will be in the position shown in the drawing. If the temperature for one reason or other exceeds the desired value, the bellows Ill will be expanded against the action of the spring I22, and the lever H9 will be turned in an anticlockwise direction. Thereby, the plate IM which is movable in a guide not shown will be displaced toward the right with the result that the pin I98 will be moved upwardly and the pin I09 will be moved downward. Thereby, the working chambers for the hot liquid will be reduced and the working .chambers for the cold liquid will be increased until the temperature of mixture again has the normal value, whereupon the different parts are moved back into the position shown in the drawings. If the temperature falls below the normal value, the apparatus will be operated in such a manner that the working chambers H will be increased and the working chambers H6 will be decreased.

It will be obvious that the device for controlling the distance between the places of connection of the bands may be subject to other influences, for instance in a manner such that the mixture of the liquids will be maintained at a desired consistency, density or the like.

The temperature of mixture may be adjusted for any desired value by varying the tension of the spring I22.

The term band is intended not only to comprise bands in the proper sense of the term, but is understood to include all structures to which a wave-like movement is imparted upon rotation of the helix or which on account of their wave-like movement impart rotational movement to the helix and which together with the walls of the casing are adapted to confine closed working chambers. Instead of a uniform band, an element may be used, which, for instance, is formed by a wire or metal strip wound about the helix in substantially rectangular coils such that the shorter inner side of the rectangle is at least equal to the diameter of the rod forming the helix and that the longer side is at least equal to the sum of the said diameter and the amplitude of the wave-like movement.

The band-like element may also be constituted by plate-like members having substantially rectangular openings for the helix and being embedded in a common member consisting of rubber or the like. In order to render possible movement of the plates while maintaining their mutual contact. at least one of the abutting surfaces of the plates is suitably curved.

In Figs. 8-11 embodiments are shown in which the bands are not constructed as uniform metal strips, but are formed by wires wound in substantially rectangular coils around the helix.

In the embodiment shown in Figs. 8-10, I28 denotes the helix and I 29 a wire the cross-section of which will be apparent from Fig. 10. The coils of the wire form rectangles the inner shorter sides of which are at least equal to the diameter of the rod forming the helix I28 and the inner longer sides of which are at least equal to the sum of the said diameter and the amplitude of the wave-like movement. Between the coils of the wire there are inserted sealing elements I372 of soft material, such as rubber, in order to prevent the formation of clearances during the wave-like movement of the band. The wire coil described operates in the same manner as two flexible metal bands disposed on difierent sides of the helix.

In Fig. 11, numeral I34 denotes the helix, I35 a wire coil in accordance with the embodiment described above, and I 36 a layer of rubber cast round the coil I35, which layer not only renders possible an efiective seal between the working chambers, but in case the working fluid consists of water considerably reduces the friction occurring between the band and the walls of the casing. If metallic contact is preferred between the band and the casing, a thin wire I31 may be wound around the rubber layer.

In Figs. 12-14 an embodiment is illustrated in which the bands are formed by plate-like members I38 which on those sides on which they are always in contact with the walls of the casing are provided with surfaces I39 bent at right angles. At their lower sides, the surfaces I39 are shaped in the form of arcs engaging corresponding arc portions of the adjacent plates such that they will be maintained in contact with one another during the wave-like movement of the band and that bending movements in the transverse direction of the band will be prevented. The plates are provided with substantially rectangular openings I49 through which extends the helix. As indicated at 22, the plates are bent downwards around the openings I40. The spaces between the parts I39 and M2 are entirely filled with rubber or the like material. As will be seen from Figs. 12 and 14, the rubber projects somewhat on both sides of the plates I 38 so that the latter are entirely embedded in the rubber. The rubber permits of twisting movement of the entire structure without separation of the plates from each other and also forms an efiective seal between the working chambers.

In the embodiments shown in Figs. 8 to 14, the helix is entirely enclosed by the band-like structure. I Such an arrangement is highly suitable due to the fact that the helix can be effectively lubricated. The helix and the enclosing band structure are movable relative to each other in two different planes with the result that lubricant enclosed in the band structure will be forced by the helix from one end of the helix to the other one so that it can be circulated through a suitable cooling device.

WhatI claim is:

1. A fluid engine comprising a casing, a flexible band therein arranged to perform a uni-directional wave-like movement, a working chamber for said fluid, said casing and said band forming separate and independent walls of said working chamber, and a helically shaped rod for cooperation with said band, said rod extending in the longitudinal direction of said casing and being rotatable about its longitudinal aids.

2. A fluid engine comprising a casing, a flexible band arranged to perform a uni-directional wave-like movement in said casing, a working chamber confined by said casing and said band and arranged upon movement of said band to be displaced longitudinally of said casing, and a helically shaped rod in power transmitting relationship to said band, the volume of said working chamber being constant at least throughout.

part of the length of said casing.

3. A fluid engine comprising a casing, two flexible bands therein arranged to perform unidirectional wave-like movements, a first working chamber confined by said casing and one of said hands, a second working chamber confined by said casing and the other one of said bands, said working chambers being arranged upon movement of said bands to be displaced longitudinally of said casing, and a helically shaped rod located between said bands in power transmitting relationship thereto.

4. A fluid engine comprising a casing, a flexible band therein arranged to perform a unidirectional wave-like movement, and a plurality of helically shaped rods positively connected to each other and extending in the longitudinal direction of said casing and being rotatable therein for cooperation with said band.

5. A fluid engine comprising a casing, a flexible band therein arranged to perform a unidirectional wave-like movement, and two helically shaped rods positively connected to each other for cooperation with said band and extending in the longitudinal direction of said casing, said rods being arranged to rotate in opposite directions, one of said rods being in the form of a right-handed helix and the other one in the form of a left-handed helix.

6. A fluid engine comprising a casing, a flexible band therein arranged to perform a unidirectional wave-like movement, end members connected to the ends of said band and pivotally mounted in said casing, means for giving the flexible band a wave-like motion, and means for imparting oscillatory movement to said end members.

7. A fluid engine comprising a casing, a flexible band therein arranged to perform a unidirectional wave-like movement, end members connected to the ends of said band and pivotally mounted in said casing, and a helically shaped rod extending through slotted portions of said end members for cooperation with said band, said rod extending in the longitudinal direction of said casing and being rotatable about its longitudinal axis.

8. A fluid engine comprising a casing, a flexible band therein arranged to perform a unidirectional wave-like movement, connecting means for the ends of said band, a movable member in power transmitting relationship to said band, and means for varying the. distance between said connecting means.

9. A fluid engine comprising a casing, a plurality of flexible bands therein arranged to perform uni-directional wave-like movements, connecting means for the ends of said bands, a movable member in power transmitting relationship to said bands, and means for separately varying the distances between the connecting means of said bands.

10. A fluid engine comprising a casing, a flexible band therein arranged to perform a unidirectional wave-like movement, connecting means for the ends of said band, a movable member in power transmitting relationship to said band, and means responsive to variations in temperature of said fluid for varying the distance between said connecting means.

11. A fluid engine comprising a casing, a tubular flexible body therein arranged to perform a uni-directional wave-like movement, and a movable member enclosed by said tubular body and in power transmitting relationship thereto.

12. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing arranged to perform a unl-drectional wave-like movement, said body consisting of wire wound in substantially rectangular coils about said rod.

13. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing arranged to perform a uni-directional wave-like movement, said body consisting of wire wound in substantially rectangular coils about said rod, the inner shorter side of the rectangle being at least equal to the diameter of said rod and the inner longer side of the rectangle being at least equal to the sum of said diameter and the amplitude of said wave-like movement.

14. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing arranged to perform a uni-directional wave-like movement, said body consisting of wire of substantially rectangular cross-section and wound in substantially rectangular coils about said rod.

15. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing arranged to perform a uni-directional wave-like movement, said body consisting of wire of substantially rectangular cross-section and wound in substantially rectangular coils about said rod, sealing elements being inserted between the abutting sides of the coils of said wire.

16. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said' casing, a flexible body in said casing arranged to perform a uni-directional wave-like movement and consisting of wire wound in substantially rectangular coils about said rod, and a cover of rubber enclosing said flexible body.

1'7. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, a flexible body in said casing arranged to perform a uni-directional wave-like movement and consisting of wire wound in substantially rectangular coils about said rod, a first cover of rubber enclosing said flexible body, and a second cover of wire enclosing said first cover.

18. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing. arranged to perform a uni-directional wave-like movement, said flexible body including a series of contiguous members having substantially rectangular openings for the reception of said rod.

19. A fiuidengine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing arranged to perform a uni-directional wave-like movement, said flexible body including a series of contiguous members having substantially rectangular openings for the reception of said rod, and a common flexible bearing member for embedding said contiguous members. I

20. A fluid engine comprising a casing, a helically shaped rod mounted for rotation in said casing, and a flexible body in said casing arranged to perform a uni-directional wave-dike movement, said flexible body including a series of contiguous members having substantially rectangular openings for the reception of said rod, the abutting surfaces of said contiguous members being curved whereby to be maintained in contact with each other during the wave-like movement of said body and to prevent movement in the transverse direction of said body.

CARL WILHELM HENRIK DiioKER BENNET. 

